1. Field of the Invention
The invention relates to a liquid crystal dropping apparatus for liquid crystal display devices, and more particularly, to a liquid crystal dropping apparatus to manufacture liquid crystal display devices, which is designed to apply vibration energy to a liquid crystal charged in a liquid crystal container, thereby allowing the liquid crystal to be dropped as a spray.
2. Discussion of the Related Art
Generally, a liquid crystal display device is formed from two substrates coupled to face each other, and a liquid crystal layer formed between the two substrates.
The two substrates bond to each other by use of a seal material so that a regular space is defined between the two substrates. The liquid crystal layer, which is formed between the two substrates, serves to control the amount of light being transmitted through the device. The liquid crystal molecules are driven by drive elements formed on the respective substrates, thereby performing the function of displaying information.
Such a liquid crystal display device is usually manufactured by either a liquid crystal injection method or a liquid crystal dropping method.
In the liquid crystal injection method, two substrates, which are respectively formed with drive elements and color filter elements, are bonded to each other with a regular distance between the substrates by using a seal material having a liquid crystal injection port. After curing of the seal material, the bonded substrates are cut per unit panel. Then, a liquid crystal material is injected into the space between the two substrates through the liquid crystal injection port.
To inject the liquid crystal material, more particularly, to inject liquid crystalline solution, into the space between the two substrates, the bonded substrates are first put into a vacuum container to create a vacuum between the two substrates. Thereafter, the liquid crystal injection port is inserted into a container in which the liquid crystal solution is contained. In such a state, if the internal pressure of the vacuum container is changed from a vacuum into atmospheric pressure, the liquid crystal solution will be injected into the space between the two substrates. After completing the injection of the liquid crystal solution, the liquid crystal injection port is sealed by use of an appropriate seal material.
On the other hand, in the liquid crystal dropping method, an appropriate amount of liquid crystal is first dropped onto any one of the two substrates. The two substrates are then bonded to each other by use of a seal material.
Hereafter, a method for manufacturing a liquid crystal display device using a related art liquid crystal injection process will be described with reference to the drawings.
FIG. 1 shows a schematic view illustrating a related art liquid crystal injection process.
As shown in FIG. 1, a liquid crystal container 102, in which liquid crystal 101 is received, is disposed and fixed inside a vacuum container 103. If multiple panels 104, which are bonded to one another and each having a liquid crystal injection port, are put into the vacuum container 103, then the internal pressure of the vacuum container 103 is kept at a vacuum pressure so as to create a vacuum between the two substrates of each panel while removing moisture and air bubbles remaining in the vacuum container 103.
Subsequently, after the liquid crystal injection port of each panel is immersed in or comes into contact with the liquid crystal 101, nitrogen (N2) gas is introduced into the vacuum container 103 to change the internal pressure of the vacuum container 103 from a vacuum to atmospheric pressure. In this case, since the interior of the vacuum container 103 is at atmospheric pressure, but the space between the two substrates of each panel 104 is still kept at a vacuum, the liquid crystal 101 will inject into the space between the two substrates through the liquid crystal injection port via the above described pressure differential.
Once the liquid crystal 101 is completely charged into each panel 104, a sealing process for sealing the liquid crystal injection port is performed. Finally, all the panels 104 are washed.
The above described liquid crystal injection process, however, has disadvantages arising from the excessively long time required to inject the liquid crystal, because the liquid crystal injection port must be immersed into or come into contact with the liquid crystal after subsequently cutting the unit panels and creating a vacuum between the two substrates of each panel. Thus, the related art liquid crystal injection process as stated above suffers from deteriorated productivity.
Moreover, in the case of manufacturing a large-area liquid crystal display device, there is a risk in that the liquid crystal is incompletely injected into the panel, causing defective products.